1. Field of the Invention
The present invention relates to a seal device for a tubular member or the like, for sealing a passage such as a tubular member at an inlet or an outlet in various containers or equipment by the use of an expanded tube.
2. Description of the Related Art
A device for gripping a bottle or the like, wherein a conventional rubber tube is expanded by injecting a fluid such as air into the tube, thereby sealing a mouth of the bottle or the like, is known. One example of such a device is disclosed on pages 4 to 5 and FIG. 1 of Japanese Patent Application Publication (JP-B) No. 7-29266. In the conventional device, both ends of a tube, into which a fluid can be injected, are respectively fixed at both ends of a single cylindrical base member. One end of the tube is fixed to a fore end of the base member, and then, the tube is folded back over itself at the fore end of the base member. In this device, the folded portion of the tube is inserted into a hole of a part, the tube is press-fitted to the inner circumferential surface of the hole by expansion, and thus, the part is gripped. If the hole of the part is a hole of a mouth of a bottle or a flask, the bottle or the like can be gripped and the mouth can be sealed.
In the conventional structure, the fore end of the base member is fitted to one end of the tube, and then, the outer periphery of the fore end of the base member is securely clamped around the tube by a clamping ring. Thereafter, the tube is folded inward (back over itself), the tube is pulled up to a base end of the base member in such a manner that the base member is covered with the other end of the tube, the other end of the tube is securely damped at the base end of the base member by a clamping ring, and thus, the folded portion of the tube is located at the fore end. The folded portion is inserted into a passage such as a tubular member or a hole formed at a part. However, in the case where the passage or the hole is curved, if the curvature is large, the tube cannot be inserted since the base member is rigid and has a predetermined length. Moreover, although it is advantageous to use a long tube or a plurality of tubes connected to each other for a passage such as a tubular member at an inlet or an outlet, in the case where the pressure inside of the container or equipment is high, it is difficult to fabricate an elongated tube having a conventional tube folding structure, and further, the folded portion makes a diameter large. Additionally, the base member also must be elongated, thereby resulting in an increase in weight, and the base member cannot be used in the case where the passage is curved.